The dual use of explicit accounting of joints and intact rock in sub-RVE size elements and implicit accounting in RVE-size elements is a practical step towards more realistic finite element modeling of jointed rock mass slope stability. Joint failure mechanisms in the small, sub-RVE size elements used near a slope face, allows recovery of joint and intact rock failure mechanisms. However, this recovery is also possible in the larger RVE-size elements used away from the slope face, provided they are jointed. In view of a surprisingly small RVE that develops when multiple joints sets are present (in this case, three). All elements in a mesh may be RVE-size. The main advantage over previous work along the same lines is greatly reduced computer run time, from hundreds of hours to several hours. This reduction allows for parametric design analysis, for example, the study of joint persistence effect. In this regard, there is a distinct possibility of increased persistence occurring during excavation that would increase the probability of formation of a linked joint collapse mechanism. Recent work by Pariseau (2006) suggest that progressive elastic-plastic damage analysis by the finite element method may be a worthy of further study with the goal of taking an additional step towards greater realism by allowing new joint formation and extension during excavation. The concept of equivalent RVE strength also needs to be explored in further detail. Finally, determination of joint persistence is a research issue in rock mechanics that needs to be addressed.
展开▼
